I'm not sure I'd quite call any philosopher my favorite, since I've yet to find any that I don't have at least one major disagreement with, but I'm pretty fond of Schopenhauer for his proto-evolutionary ideas, his philosophy on will and motivation, and his views on art.

If we are to judge all of Philosophy, there comes to mind a Triumvirate, who work, so profound, has set the standards and the tone of all philosophy- Plato, Aristotle, and Kant. All of Philosophy, ancient and modern, can be directly linked to any of, or all of, the three- St. Thomas Aquinas, for example, used Aristolian Physics and Logic extensively to write his Summa Theologica, the entire current of Western Esotericism- Gnosticism, Hermeticism, etc., can be traced back to, ultimately, Plato's Timaeus, the Cynics, and the Stoics who were derived from the Cynics, and Epictetus from the Stoics, all can be seen as a reaction against Plato's towering genius, Nietzsche, Schopenhauer, Hegel can be simply seen as an attempt to rise above the giant Kant, and none successfully.

If we are to judge all of Philosophy, there comes to mind a Triumvirate, who work, so profound, has set the standards and the tone of all philosophy- Plato, Aristotle, and Kant. All of Philosophy, ancient and modern, can be directly linked to any of, or all of, the three- St. Thomas Aquinas, for example, used Aristolian Physics and Logic extensively to write his Summa Theologica, the entire current of Western Esotericism- Gnosticism, Hermeticism, etc., can be traced back to, ultimately, Plato's Timaeus, the Cynics, and the Stoics who were derived from the Cynics, and Epictetus from the Stoics, all can be seen as a reaction against Plato's towering genius, Nietzsche, Schopenhauer, Hegel can be simply seen as an attempt to rise above the giant Kant, and none successfully.

I'll hazard that Descartes could replace Kant there. Kant is the superior philosopher, but Descartes set the stage for a lot of early modern philosophy by making (foundationalist) epistemology the 'first' philosophy upon which everything else needs to rest (and this is also, I think, one of the supreme instances of philosophy shooting itself in the foot). The empiricists, Kant and the German Idealists, Nietzsche and the postmodernists were all responding to this in some fashion or other.